1. Field of the Invention
The present invention relates to a rapid dehydrating/drying device usable in low temperature which can perform extremely efficiently and economically due to energy-savings. A dehydrating/drying device of the present invention uses a high speed fluid for drying sheet-type articles such as mats, carpets, fabrics, clothes, non-woven fabrics, synthetic resin film, glass, cardboard and printed articles or hoses.
2. Description of the Prior Art
Natural drying, ventilation drying, heated drying, high frequency heated drying, centrifugal dehydration drying, dehydrating/drying by pressurizing, heated drying using a rotary drum, and vacuum drying using pressure decrease have been used for drying mats, carpets, sheets and clothes. These drying methods require large amounts of heat energy and a great deal of time.
A flat mat such as a household foot mat, a business-use door mat or a carpet has various fibers implanted on a sheet surface of, for example, reinforcing rubber, etc., or has fabrics adhered to the surface of, for example, the rubber sheet. These types of mats are extremely hard to dry since they have no air passage in the direction of their thickness.
For the above-mentioned articles to be dried, natural drying and hot air drying require a long period of time. During heated drying using a rotary drum an article to be dried is put in a drum which is rotated. Hot air for drying is input into the drum. Mat fibers are damaged by friction and cracks are generated in the rubber sheet base material on the back of the mat. When high temperature wind is used, a great deal of heat energy is required and at the same time the mat fibers are deteriorated by the heat which substantially shortens their lives.
During vacuum drying using pressure decrease, vapor pressure in a vacuum vessel is decreased to evaporate the humidity contained in an article to be dried. As the article to be dried is dried taking away evaporation heat, it is cooled and sometimes it is frozen. Then it must be heated. Thus this method has a defect that a great deal of heat energy and motion power for a vacuum pump are needed and at the same time the drying time is long.
To eliminate the above defects, the applicants of the present invention proposed a low temperature rapid dehydrating/drying device in Japanese Patent Applications No-126742/1994 and No-222403/1994.
Japanese Patent Application No. 126742/1994 is directed to dehydrating/drying an article to be dried by finely dividing the water adhering to a wet mat into minute water drops by using only a negative pressure air stream or a negative pressure air stream and a high speed air jet stream. The minute water drops are sucked and removed from the wet mat. Japanese Patent Application No-222403/1994 is directed to a device that can continuously dehydrate/dry in low temperature in a short time by installing flanges in circumferential parts of a sucking-out opening and/or a blowing opening to prevent fluid from flowing into both nozzles thus forming a short cut with a high speed negative pressure air stream and outer air. Rather, the high speed air jet stream and the high speed negative pressure air stream reach deeply into the root of the fibers due to the acceleration of the high speed negative pressure air stream by the multiplication effect of the high speed air jet stream and the high speed negative pressure air stream.
The rapid dehydrating/drying device mentioned above can dehydrate/dry in extremely highly efficient manner when the width of the mat is almost the same as the widths of the sucking-out nozzle and of the blowing nozzle. But, when the width of the mat is narrower than the widths of both nozzles (the blowing nozzle and the sucking-out nozzle), the high speed air jet stream and the negative pressure air stream can freely flow in and out where the mat is not touching both nozzles, i.e., an open part of both nozzles where the mat is not covering both nozzles (hereinafter referred to as the open part).
Therefore, when flowing volume increases according to a P-Q curve (P is pressure (mmAq), Q is flowing volume (m.sup.3 /hr)), blowing pressure and sucking-in pressure decrease dramatically to make it impossible to secure a high speed air jet stream and a high speed negative pressure air stream necessary for drying the mat. Thus, the time for drying the mat becomes very long.